Why do our bodies do the exact opposite of what we need when we're stressed?

Maybe it's just my body, but when I'm stressed my body acts out and makes it worse
  1. Hey! Are you feeling stressed?
    Now your stomach hurts.
  2. Hey! Are you feeling stressed?
    Now your head hurts.
  3. Hey! Are you feeling stressed?
    Now your neck hurts! Bwahahaha!
  4. Hey! Are you feeling stressed?
    You just thought you were getting sleep tonight!
  5. Hey! Are you feeling stressed?
    Now that you're finally asleep, you're going to dream about spiders (which I'm very afraid of!) all night long! Big ones, too. Enjoy that restless sleep!
  6. Hey! Are you feeling stressed?
    Now your milk production is going to take a nosedive! You're welcome!
  7. Hey! Are you feeling stressed?
    Yes, yes I am! Please stop. 🙄